/* Copyright (c) 2011, Carl Burch. License information is located in the
 * com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */

/**
 * Based on PUCTools (v0.9 beta) by CRC - PUC - Minas (pucmg.crc at gmail.com)
 */

package com.cburch.logisim.std.wiring;

import java.awt.Color;
import java.awt.Graphics2D;

import com.cburch.logisim.circuit.Wire;
import com.cburch.logisim.data.Attribute;
import com.cburch.logisim.data.AttributeSet;
import com.cburch.logisim.data.BitWidth;
import com.cburch.logisim.data.Bounds;
import com.cburch.logisim.data.Direction;
import com.cburch.logisim.data.Location;
import com.cburch.logisim.data.Value;
import com.cburch.logisim.instance.Instance;
import com.cburch.logisim.instance.InstanceFactory;
import com.cburch.logisim.instance.InstancePainter;
import com.cburch.logisim.instance.InstanceState;
import com.cburch.logisim.instance.Port;
import com.cburch.logisim.instance.StdAttr;
import com.cburch.logisim.tools.WireRepair;
import com.cburch.logisim.tools.WireRepairData;
import com.cburch.logisim.tools.key.BitWidthConfigurator;
import com.cburch.logisim.util.GraphicsUtil;
import static com.cburch.logisim.util.LocaleString.*;

public class TransmissionGate extends InstanceFactory {
    static final int OUTPUT = 0;
    static final int INPUT = 1;
    static final int GATE0 = 2;
    static final int GATE1 = 3;

    public TransmissionGate() {
        super("Transmission Gate", getFromLocale("transmissionGateComponent"));
        setIconName("transmis.svg");
        setAttributes(new Attribute[] { StdAttr.FACING, Wiring.ATTR_GATE, StdAttr.WIDTH },
                new Object[] { Direction.EAST, Wiring.GATE_TOP_LEFT, BitWidth.ONE });
        setFacingAttribute(StdAttr.FACING);
        setKeyConfigurator(new BitWidthConfigurator(StdAttr.WIDTH));
    }

    @Override
    protected void configureNewInstance(Instance instance) {
        instance.addAttributeListener();
        updatePorts(instance);
    }

    @Override
    protected void instanceAttributeChanged(Instance instance, Attribute<?> attr) {
        if (attr == StdAttr.FACING || attr == Wiring.ATTR_GATE) {
            instance.recomputeBounds();
            updatePorts(instance);
        } else if (attr == StdAttr.WIDTH) {
            instance.fireInvalidated();
        }
    }

    private void updatePorts(Instance instance) {
        int dx = 0;
        int dy = 0;
        Direction facing = instance.getAttributeValue(StdAttr.FACING);
        if (facing == Direction.NORTH) {
            dy = 1;
        } else if (facing == Direction.EAST) {
            dx = -1;
        } else if (facing == Direction.SOUTH) {
            dy = -1;
        } else if (facing == Direction.WEST) {
            dx = 1;
        }

        Object powerLoc = instance.getAttributeValue(Wiring.ATTR_GATE);
        boolean flip = (facing == Direction.SOUTH || facing == Direction.WEST)
            == (powerLoc == Wiring.GATE_TOP_LEFT);

        Port[] ports = new Port[4];
        ports[OUTPUT] = new Port(0, 0, Port.OUTPUT, StdAttr.WIDTH);
        ports[INPUT] = new Port(40 * dx, 40 * dy, Port.INPUT, StdAttr.WIDTH);
        if (flip) {
            ports[GATE1] = new Port(20 * (dx - dy), 20 * (dx + dy), Port.INPUT, 1);
            ports[GATE0] = new Port(20 * (dx + dy), 20 * (-dx + dy), Port.INPUT, 1);
        } else {
            ports[GATE0] = new Port(20 * (dx - dy), 20 * (dx + dy), Port.INPUT, 1);
            ports[GATE1] = new Port(20 * (dx + dy), 20 * (-dx + dy), Port.INPUT, 1);
        }
        instance.setPorts(ports);
    }

    @Override
    public Object getInstanceFeature(final Instance instance, Object key) {
        if (key == WireRepair.class) {
            return new WireRepair() {
                @Override
                public boolean shouldRepairWire(WireRepairData data) {
                    return true;
                }
            };
        }
        return super.getInstanceFeature(instance, key);
    }

    @Override
    public Bounds getOffsetBounds(AttributeSet attrs) {
        Direction facing = attrs.getValue(StdAttr.FACING);
        return Bounds.create(0, -20, 40, 40).rotate(Direction.WEST, facing, 0,
                0);
    }

    @Override
    public boolean contains(Location loc, AttributeSet attrs) {
        if (super.contains(loc, attrs)) {
            Direction facing = attrs.getValue(StdAttr.FACING);
            Location center = Location.create(0, 0).translate(facing, -20);
            return center.manhattanDistanceTo(loc) < 24;
        } else {
            return false;
        }
    }

    @Override
    public void propagate(InstanceState state) {
        state.setPort(OUTPUT, computeOutput(state), 1);
    }

    private Value computeOutput(InstanceState state) {
        BitWidth width = state.getAttributeValue(StdAttr.WIDTH);
        Value input = state.getPort(INPUT);
        Value gate0 = state.getPort(GATE0);
        Value gate1 = state.getPort(GATE1);

        if (gate0.isFullyDefined() && gate1.isFullyDefined() && gate0 != gate1) {
            if (gate0 == Value.TRUE) {
                return Value.createUnknown(width);
            } else {
                return input;
            }
        } else {
            if (input.isFullyDefined()) {
                return Value.createError(width);
            } else {
                Value[] v = input.getAll();
                for (int i = 0; i < v.length; i++) {
                    if (v[i] != Value.UNKNOWN) {
                        v[i] = Value.ERROR;
                    }
                }
                return Value.create(v);
            }
        }
    }

    @Override
    public void paintInstance(InstancePainter painter) {
        drawInstance(painter, false);
        painter.drawPorts();
    }

    @Override
    public void paintGhost(InstancePainter painter) {
        drawInstance(painter, true);
    }

    private void drawInstance(InstancePainter painter, boolean isGhost) {
        Bounds bds = painter.getBounds();
        Object powerLoc = painter.getAttributeValue(Wiring.ATTR_GATE);
        Direction facing = painter.getAttributeValue(StdAttr.FACING);
        boolean flip = (facing == Direction.SOUTH || facing == Direction.WEST)
            == (powerLoc == Wiring.GATE_TOP_LEFT);

        int degrees = Direction.WEST.toDegrees() - facing.toDegrees();
        if (flip) {
            degrees += 180;
        }

        double radians = Math.toRadians((degrees + 360) % 360);

        Graphics2D g = (Graphics2D) painter.getGraphics().create();
        g.rotate(radians, bds.getX() + 20, bds.getY() + 20);
        g.translate(bds.getX(), bds.getY());
        GraphicsUtil.switchToWidth(g, Wire.WIDTH);

        Color gate0 = g.getColor();
        Color gate1 = gate0;
        Color input = gate0;
        Color output = gate0;
        Color platform = gate0;
        if (!isGhost && painter.getShowState()) {
            gate0 = painter.getPort(GATE0).getColor();
            gate1 = painter.getPort(GATE0).getColor();
            input = painter.getPort(INPUT).getColor();
            output = painter.getPort(OUTPUT).getColor();
            platform = computeOutput(painter).getColor();
        }

        g.setColor(flip ? input : output);
        g.drawLine(0, 20, 11, 20);
        g.drawLine(11, 13, 11, 27);

        g.setColor(flip ? output : input);
        g.drawLine(29, 20, 40, 20);
        g.drawLine(29, 13, 29, 27);

        g.setColor(gate0);
        g.drawLine(20, 35, 20, 40);
        GraphicsUtil.switchToWidth(g, 1);
        g.drawOval(18, 30, 4, 4);
        g.drawLine(10, 30, 30, 30);
        GraphicsUtil.switchToWidth(g, Wire.WIDTH);

        g.setColor(gate1);
        g.drawLine(20, 9, 20, 0);
        GraphicsUtil.switchToWidth(g, 1);
        g.drawLine(10, 10, 30, 10);

        g.setColor(platform);
        g.drawLine(9, 12, 31, 12);
        g.drawLine(9, 28, 31, 28);
        // arrow
        if (flip) {
            g.drawLine(18, 17, 21, 20);
            g.drawLine(18, 23, 21, 20);
        } else {
            g.drawLine(22, 17, 19, 20);
            g.drawLine(22, 23, 19, 20);
        }

        g.dispose();
    }
}
